Paul was discussing circumcision and uncircumcision. He was making the point that the same God of Israel is the same God of the new creation-—Christians.
I asked you read Genesis 12 and 17. Between both references there ARE promises made to Abraham that apply to those in Christ Jesus. There are those that do not and they are specifically to Israel.
If we are to do a full transfer of the unconditional promises stated then all Christians own the land of Canaan. We would also have to discard many OT prophecies yet fulfilled (last chapters of Ezekiel, Zechariah, Joel et al) and say since Israel as a nation rejected Jesus Christ, Oracles of God will not be fulfilled.
“There are those that do not and they are specifically to Israel.”
Paul tells us who the true Israel is, it is comprised of FAITH not Flesh. if someone wants to believe 19th century doctrinal innovations called dispensationalism, feel free.
Romans 9:6 for not all who are descended from Israel BELONG TO ISRAEL.